Protective effect of abamectin on acute lung injury induced by lipopolysaccharide in mice

Abamectin, a broad-spectrum antiparasitic agent, has been shown to exert an anti-inflammatory effect, in vitro, by down regulating both the nuclear transcription factor kappa-B and the mitogen-activated protein kinase (MAPK) activation pathway. In this study, we investigated the role of abamectin in acute lung injury (ALI) induced by Lipopolysaccharide (LPS), and the invovment of MAPK and NF-kappa B. BALB/C mice were administered abamectin (PBS) orally, followed by a dose of 0.5 mg/kg of LPS. After 10 h, tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) in bronchoalveolar lavage fluid (BALF) were measured using enzyme-linked immunosorbent assay. The number of total cells, neutrophils, and macrophages in the BALF were determined. The right lung was then excised for histological examination and analysis of myeloperoxidase (MPO) activity. Phosphorylation of MAPK family and I kappa B were detected by western blot. We found that 2 mg/kg of abamectin had significant protective effects on ALI. Mice treated with LPS alone showed markedly increased TNF-alpha and IL-6 levels in the BALF. In addition, not only was the W/D ratio of lung tissue significantly decreased, the number of total cells, neutrophils and macrophages in the BALF was also significantly reduced 11 h after treatment with abamectin. Furthermore, p38MAPK, ERK, and I kappa B were activated in 10 h after LPS treatment, which could be blunted by Abamectin. These results indicate that abamectin could attenuate inflammatory injury induced by LPS through MAPK and NF-kappa B passway.